Service function chaining congestion feedback

Abstract

A method of reporting congestion in an upstream direction in a service chain function architecture. The method includes receiving, by the downstream device, a packet indicating congestion within a service function chaining architecture; generating, by the downstream device, a congestion report message in response to receiving the packet, wherein the congestion report message comprises a field indicating an existence of congestion within the service function chaining architecture and a service path identifier indicating a location of the congestion within the service function chaining architecture; and transmitting, by the downstream device, the congestion report message to an upstream device to permit the upstream device to address the congestion.

The invention claimed is: 
     
       1. A method of reporting congestion to an upstream device implemented by a downstream device, comprising:
 receiving a packet indicating congestion on a path within a service function chaining architecture; 
 generating a congestion report message in response to receiving the packet, wherein the congestion report message comprises a field indicating an existence of congestion within the service function chaining architecture and a service path identifier indicating a flow of the congestion within the service function chaining architecture; and 
 transmitting the congestion report message to the upstream device to permit the upstream device to alleviate the congestion, wherein the upstream device includes a classifier configured to meter or direct a flow of packets in response to receiving the congestion report message from the downstream device, 
 wherein the packet comprises a plurality of unused bits fields, and wherein at least two of the unused bit fields contain a value to indicate the congestion within the service function chaining architecture. 
 
     
     
       2. The method of  claim 1 , wherein the value is represented by one or more binary numbers. 
     
     
       3. The method of  claim 1 , wherein the downstream device is an exit node in the service function chaining architecture. 
     
     
       4. The method of  claim 1 , wherein the downstream device is a service function forwarder (SFF) in the service function chaining architecture. 
     
     
       5. The method of  claim 1 , wherein the packet comprises a network service header (NSH) and the congestion report message includes a modified version of the NSH. 
     
     
       6. The method of  claim 5 , wherein the modified version of the NSH identifies a meta data (MD) type, and wherein meta data corresponding to the MD type is structured as one or more fields or type length values (TLVs). 
     
     
       7. A method of reporting congestion to an upstream device implemented by a downstream device in a service function chaining architecture, comprising:
 receiving a packet containing two congestion bits that have been set in a network service header (NSH); 
 generating a congestion report message in response to receiving the packet, wherein the congestion report message indicates an existence of congestion on a path within the service function chaining architecture and a flow of the congestion within the service function chaining architecture; and 
 transmitting the congestion report message to the upstream device within the service function chaining architecture, wherein the congestion report message instructs the upstream device to address the congestion, wherein the upstream device includes a classifier configured to meter or direct a flow of packets in response to receiving the congestion report message from the downstream device. 
 
     
     
       8. The method of  claim 7 , wherein the existence of the congestion is indicated by manipulating at least one field in the NSH of the packet and including the at least one field in the congestion report message when generated. 
     
     
       9. The method of  claim 7 , wherein a location of the congestion is indicated by manipulating a service path identifier in the NSH of the packet and including the service path identifier as manipulated in the congestion report message when generated. 
     
     
       10. The method of  claim 7 , wherein the downstream device is an exit node in the service function chaining architecture. 
     
     
       11. The method of  claim 7 , wherein the downstream device is a service function forwarder (SFF) in the service function chaining architecture. 
     
     
       12. An upstream device in a service function chaining architecture, comprising:
 a memory comprising instructions; 
 a processor in communication with the memory, wherein the processor executes the instructions to:
 transmit a packet to a downstream device; 
 receive a congestion report message from the downstream device in response to transmission of the packet, wherein the congestion report message comprises a field indicating an existence of congestion within the service function chaining architecture and a service path identifier indicating a flow of the congestion within the service function chaining architecture; and 
 alleviate the congestion identified in the congestion report message, wherein the processor executes the instructions to meter or direct a flow of packets in response to receiving the congestion report message from the downstream device, 
 wherein the packet comprises a plurality of unused bits fields, and wherein at least two of the unused bit fields contain a value to indicate the congestion within the service function chaining architecture. 
 
 
     
     
       13. The upstream device of  claim 12 , wherein the value is represented by one or more binary numbers. 
     
     
       14. The downstream device of  claim 12 , wherein the downstream device is an exit node in the service function chaining architecture. 
     
     
       15. The downstream device of  claim 12 , wherein the downstream device is a service function forwarder (SFF) in the service function chaining architecture. 
     
     
       16. The downstream device of  claim 12 , wherein the packet comprises a network service header (NSH) and the congestion report message includes a modified version of the NSH.